DESCRIPTION: The specific aims of the Prevention and High Risk Studies Unit are to: 1) Establish an infrastructure to recruit and prospectively follow two independent populations of adolescents at risk for schizophrenia: one at genetic risk; the other at clinical risk. 2) Establish valid and reliable screening procedures for identifying high- risk populations of interest. 3) Develop and validate predictor profiles derived from the information collected from both the clinical and genetic at-risk subjects, including: A pre-psychosis predictor profile, consisting of both non-specific and attenuated schizophrenia-like clinical signs and symptoms as well as neurocognitive predictor deficits. A profile for pre-illness prevention consisting of early developmental abnormalities (especially in the neurocognitive, neuropsychological and physiological domains). 4) Pilot new pharmacological strategies for pre-psychosis preventive intervention.